X-ray apparatus



w. WATSON April 9, 1940.

X-RAY APPARATUS Filed Sept. 7, 1939 5 Sheets-Sheet 1 m er y a 5 W x M wW 7 a April 1940- w. WATSON 2,196,618

X*RAY APPARATUS Filed Sept. '7, 1939 5 Sheets-Sheet 2' April 9, 1940.

W. WATSON X-RAY APPARATUS 5 Sheets-Sheet 3 w. WATSON April 9, 1940.

-RAY APPARATUS Filed Sept. '7, 1939 5 Sheets-Sheet 4 April 1940- w.WATSON 2,196,618

X-RAY APPARATUS Filed Sept. 7, 1939 5 Sheets-Sheet 5 INVENTOR um/vh/flrso/v.

jw w

ATTORNEY UNITED, S A

Patented App- 9;, i940 i x-RAY APPARATUS Y.

William The Medical London, England, assignor to .Supply AssociationLimited,

' London, England, an association of Great Britain ApplicationSeptemberi In Great Britain This invention relates to X-,-ray apparatus and moreparticularly to apparatuswhich may be employed for so-calleddifferential radiography.

. Differential radiography is distinguished from is Tomograph apreselected plane in the X-ray tube is moved relatively to the-objectduri normal radiographyiby the fact that the resultant radiographs aresubstantially true representations of matters lying in a preselectedplane of the irradiated object, matters lying in'redundant planes,

1. e. planes not selected, being blurredor other.- wisedistorted.v l 1Apparatus'for differential radiography has been proposed inseveralforms, amongst which there apparatus. In this latter appathedesired image of irradiated object, the

ratus, in order to secure ing exposure of the film and the latter ismoved in correspondence with the source of X-rays to secure theselective recording of a particular plane of the irradiated object.

It is the chief object of the invention to afford apparatus of the typegenerally indicated above,

but whichwill afford better results, or results of better diagnosticvalue, whilst essentially im-- ,plifying the nature of the apparatusrequired.

In accordance with the present invention, there isprovided apparatus foruse in conjunctionwith an (X-ray tube to secure a recording of aparsection vor sections) of the object orj-body upon,

ticular plane, or planes,

tion', wherein the source of X-rays, the means for supporting the objector patient and the recording means are all arranged in such manner Ithat a "preselected plane or planes (section or sections) of the objectmy be irradiated and an thereof produced on. the re being adapted foranimage or images cording means, the latter gular movement up'to orbeyond 360 and either the body undergoing irradiation or the source ofthe X-rays being similarly adapted for. perform; ingqa like angularmovement, the angular movement of 'the recording means and theirradiated body or the tube, being so co-ordinated that. during suchangular movement the; image, or

images,. oi.the preselected plane or planes (or the recording meansremains stationary rela:

tively to said recording means;

in order that the said invention mayfbe clearly gunderstood and readily.

same willnow be more fully described. with ref.-

carried into effect, the

erence to, the accompanying drawings, in which;

partly in section, or a. part-ofg-an,apparatus for carrying out the inj'1 Figure H1 is fa side view,

I or section, 01" sections, through an object or patient to undergoirradiahollow to allow mecha '1, 1939; Serial Nt. 293,720

December 29, 193': i

8 Claims. h (Cl. 256-415) Figures 2, 3 and tare respectively sidepplanparts being omitted for clarity.

film holder or cassette whichmay be employed Fig. 5* is a:perspectivefview of a support for a and inverted plan views of theapparatus, certain 15? with the present apparatusior the making of 1 aradiograph or a single section-or plane of an object; t

Fig. 6 is a, bottom view of alplatform ttachane tothe apparatus-forsecuring the support of 5 to the apparatus; I I

,Fig. 7 is aperspective view of the top of the platform as shown in Fig.6;

Fig. 8 islaperspective v1ew.of a modification oi the support as shown inFig. fiforsupporting' planes of anobject tobe simultaneously radioer pd;

port such as shownbetween the top and bottomplates as shown, forexample, inFig.8; f

Fig". l l is an elevationalview of a grid such as may be employed withthe present invention ter illustrate the mechanism;

Fig. l5 is a sectional few further modification of a film support whichmay be employed in connection with the present invention a plurality offilms to enable several sections or looking down on a.

Figs. 9 to 13,]inclu sive, are sectional views showing variousothermodifications which the sup I in Fig. 8 may take,fsuch' views beingtaken on asectional line midway having part of. the structure brokenaway to bet- Fig, 16 is a. sectional view taken onthe XVI-XVI of Fig.15; Fig. 17 is a diagrammatic illustration of the apparatus of thepresent invention for the taking plane of an. object a Fig. 18 is, adiagrammatical illustration of the v 4O apparatus of the presentinventionior the taking of a radiograph of a single horizontal sectionor.

of a radiographof a plurality of verticalsections or planes of. anobject simultaneously when-em ploying a film holder such as shown inFig, 8;1

Fig. 19 is a further diagrammatical illustration. showingvarious angularpositions of the filmforthe taking of a section-or plane of the objectto beradiographedparallel to the plane of the film,

and

to diagrammatically illustrate the positions of the sensitized filmswhen 'tive' supports as shownin Figs. 9 to 13, inclusi've.

. 1 Figs. 20 to 24, inclusive,v are perspectiveviews a 9.. disposed inthe respec-.

, Referring first to Figures lto 14 ,the' apparatus generally consistsoi a base member .Lwhich is beneath. The base member l has a slot 2 overwhich there is seated a column 3. The base of the column 3 enters theslot 2 and is guided therein. There is a hand adjusting mechanism 4whereby the columnS may be clamped in any position of adjustment alongthe slot The column is "hollow and receives a hollow shaft 5, the lowerend ii of which has a spigot I screwed into it, such spigot projectingthrough i the slot 2 and carrying fixedly a sprocket wheel 8. There isa'thrust bearing 9 arranged to permit thehollow shaft 5 to be turnedwith ease with reference to the column 3 even though there may be avertical load upon the saidhollow shaft. Within the hollow of the shaft5 there is accommodated a tube Ill, the adjusted position of which, in avertical direction, .isporitrolle'd The tube lilin turn' I! of.the'turntable. The shaft lB'passes through the" base plate! and carriesat its lower end fixedly a sprocket wheel'29 which'will-be seen to" bein alignment with the sprocket 8 associ ated with the column In additionto the sprockets Ziland ii, there are two further sprockets 2| and 22which are shown in the inverted plan view of Figure 4. There are rigidlinks 23' extending "between the shafts 'l "and 59, such links looselyengaging the shafts so as 'not to interfere with the angular movementthereof.

The links 23 also engage short spindles M and 25'which support-thesprockets Til and-22f There is an endless'chain'tii engaging all thesprockets The turntable 51 on its upper side has a pair of verticalsupports 2? and '28 which, at; their upperends," are joined by-ahorizontal bar as.

There is a-semi-cylin'dricahscreen-or support 39 arranged in conjunctionwith the frame-work consisting of themembers EH28 and 29., With theapparatus so far described, it will be under-' stood that if the system-of-telescopic supporting;

tubes withinthe column 3 is moved angularly, then the sprocket '8associated therewith will be similarly angularly moved and the-chainZtiwill cause the turntable l1 to movein like manner. If-it is desiredto adjust the position of the column 3 along-the slot-2,this may be doneby slackening off the screw clampingmechanism l {and pushing'the columnB towa'r-dsthe desired position of adjustment. The links .23 will servealways to keep the chain 26taut, so that any angular movement of thetelescopic supporting system within the column 3 will always result inacorrespo'nding angular movement ofthe. turntable and vice versa. 1 Thetelescopic'system of tubes carried by the column 3 is intendedtosupport-a cassette or film carrier which may.

be designed in various ways as will be explained with reference to theother figures of the draw ings. For the purpose of describing the actionof the apparatus of Figures 1 to 4 ;it will be "assumed that -the simpletable shown in Figure l posed filmin'ahorizontal plane. Then,to-complete" theiilustrated apparatusand -to-r'ender*it-- at'lfijreceivesa' cassette'ada'pted to hold-an exoperablegan X-ray tube'ofknownconstruction and type is disposed behind the turntable IT in suchmanner as to produce an X-ray beam that passes over the turntablev andis directed upon the horizontal film within the cassette car-. ried bythe table It, such as shown in Fig. 17. There is a grid carrieriiidisposed between the column 3. and the turntable ll; The grid. car.-rier 3i consists of two parallel, Spaced uprights which are braced as at32 at their lower ends, aridwhich serve to support between them the grid33 (see Figure 14). l The grid 33 is carried in a frame t ifwhich issupported on pivots 35 connected with'a further frame 36. The frame 36is in turn supported by pivots 3? which are secured to sliders 38 whichwork upon the uprights ofthe supporting structure 3!. Thesupporting-uprights 3! are provided with cable and pulley mechanismassociated with counterweights whereby the grid may/be readilyadjustedin a verticaldirection on its-supports. It will'be understoodthat with the disposalof the grid 33 in the way described, thelatter-may be moved to any convenient angle of adjustment so as tosecure always the optimum effect of the grid.

With the grid disposed in the manner indicated, and positionedforexample in the way shown in Figure lythe vX-ray tube causes a beam ofXrays to pass over the top of .the

turntable ll and to pass: through the-grid-and to irradiate the filmsupportedby, the table l5. In describing the intended use of theapparatus, it will be supposed that a patient is standing upon theturntable ll or is supported by a saddle seat thereon (not shown). Thebeam of X-rays will pass obliquely through the body of-the patientcarried by the turntable'l'l and a corresponding shadow in a horizontalplane will fall upon the horizontally. supported'film as can be seen inthe diagrammati'c illustration of Fig. 17. If now the turntable ll berotated so that the patient thereon is subject to an angular movement,then similarly the filmcarried by the platform will besubject to a.similar angular movement. and there viill be recorded upon thefilmtarecord of a horizontal section through the patient at aparticularly vertical'height. Upon the film there will also be recordedin a distorted or blurredmanner other parts than that which j it isspecifically desired to record. It will, however, be understood thatonly one preselected horizontal plane will be recorded upon the film ina clear and distinct manner. .Such plane may be variedby varyinghorizontal"height of the platform I5 carrying the-film and also theangle of the incident beam of X-rays. .Thus a sectional picture along a;horizontal plane through anydesired portion of the patientis body maybesecured.

Itwill be further'seenqfrom Fig. 17 that the film axis and object axisremain parallel to each other at all times. Also to project an imageupon the film of a-horizontal plane of the object; the optical axis ofthe X-ray beam must be above the level of the film so-that the X- raybeam will have a downward direction; The height oftheobjective plane isalways 'atthe level where the optical axis of the X-ray beam'intersectsthe object axis. The optical axis of. the X-ray beam is a'line joiningthe focus to the intersection of the film by its own axis as can be seenin Fig. 17. Raising the X-ray tube and the film a'similar amountraisesthe'heightof the objective plane I equally: A variation in the height ofthe-filing 'only or varying the object-film distance alters the heightof the objective plane. 'An 'altera-- axis as the film has to the filmaxis. Moreover,

itcan be appreciated from Fig. 17 that themagnification of theimage ascompared to the object remains constant so long as the focus-objectdistance-and the object-film distance remain constant and even thoughthefocal-film distance varies perpendicular relative to the film, or theangle of projection is altered, provided the objective plane is parallelto the film. Thus to change the magnification factor of the image'it isonly necessary to alter either the focus-object:

or the object-film distance.

In the drawings no means has been illustrated for turning the turntable11. It will, however, be understood that the turning movement may beobtained by hand or, alternatively, by means of an automatic drive froman electric motor. The angular distance through which the turntable isrotated may be varied according to technical requirements and dependingupon the nature of the body that is being irradiated by the X-rays.Thus, if for example a metal casting is being examined'and not the bodyof a patient, it may be desirable to set the turntable and the platformcarrying the film into rotation over a considerable angular distance ofas much as 360 degrees. On the otherhand, a rotation through only ashort angular distance of about 180 degrees may be desired. In the casewhere a short angular distance of exposure of the film .is desired, theturntable l1 may be formed with a plurality of radially disposedapertures into which there may fit pegs 40 and 4|. There is an electricswitch 42 located adjacent the turntable l1 and provided with anoperating star member 43 with which the pins .40 and 4| may co-operate.The electric switch 42 serves to control the X-raytube so that if, forexample, the turntable. is rotating in anti-clockwise direction, asseenin Figure 3, then the arrangement would be such that when the" pin 40 isbehind the switch 42,-

with reference to the intended direction of movement ofthe-turntable,then. on the initial movement of the pin 40 itwill co-act with theswitch 42 to bring the X-ray tube into operation, such tube remaining inoperation until the peg 4| passes the switch 42, whereupon the member 43will again be operated to cut off the source of X-rays. v I

In the above, reference has been made particularly to the making ofhorizontal sectional radiographs. It will be realised that the apparatusdescribed is not limited to'this use. The table or platform I5 maycarry'a vertically disposed cassette supporting a film in a verticalplane, such as shown inFig. 6.v The beam of" X-rays will now be arrangedsoas to pass through" the grid 33jand to irradiate the film and thepatient, or object, upon the turntable with a beam that is substantiallyperpendicular to the vertical film. If the filmis located-in a .verticalplane containing the axis of rotation of thetable I5, then asectionthrough the patient consisting of a vertical plane including the axis.of rotation of the turntable wouldberecorded, The image willthus beperspectively .the same as. that seen by thenaked eye fromthe positionof the focus,

butif the optical axis of the X-ray beam is not.

perpendicular to the film, then the image exhibits distortion in-depthonly with that portion or section of the object parallel to the'filmtrue to shape from any point of a hemisphere atwhich itxis practicableto place. the focus. It is, however, not necessary to dispose the filmin a vertical plane containing the axis of rotation of the turntable. Ifthe film is disposed in a vertical after more fully described withreference to Fig. 3

5. the following, several types offilm holders will'be described to showthe several methods of.

operation offthe, apparatus. It will, however, be understood that theexamples of construction of the various typesoiv film holders have by nomeans been, exhausted and other possibilities arise. There isfirst thetype of platform generally shown in'Figures l and 15, and moreparticularly, shownin Figures 6 and?) The platform consists of a'basemember 44 having the spigot l4 and brackets 45.- The brackets 45 haveelongated fixing slots 46' adapted for co operation with screw clamps41', whereby an adjustment may be made forthe reception of various sizesof, cassette. Theplatform described is suitable for the reception of ahorizontally disposed cassette and film.

In Figure 5 there is shown a type of platiorm for supportgoia verticalfilm holder. There is a base member, 48 provided with a spigot (notshown) and havingv channel section ends 49. The

channel section ends 4.? permit a framework to be slid therein ,andbrought-tovarious positions of adjustment. The framework essentiallyconsists of a base member 58 having uprights 5| which carry pivotscr'ews52 for thesupport of a rectangularframe'iii. The frame 53 is adapted.toreceive a cassette or film holder (or an equiv--.

alent screen,which remark applies where a film is mentioned herein forobvious reasons), There may be an arbitrary scale 54 adapted toco-oper-.

ate with the film holder for the purpose of allowing determination ofthe relative, or absolute distance of recorded sections. It will .beunderstood that the film carried in thisholder may be located in avertical plane either on the vertical axis or any distance from thecentre of-rotation of the-supporting table as above noted and, fur,

thermore, the film may be obliquely. placed if so desired. In otherwords the film maybe positioned in any angular position,such as shown inFig. :19, and regardless of the angulationof the X ray beam, thatportionof the object parallelv to the film will be well defined with allotherportheifilm may be oblique or at right angles to the axis. can becurved or bent to any reasonable shape.

Also," a number of films in, any desired spacial relation may besimultaneously exposed, each film recording a different section of theobject,

,' or a continuous length of film maybe used to recorda continuousspiral section of increasing depth. l I

.In Figure 8 there is shown a holderadapted to; receive a plurality ofrecording There Furthermore, the film need not be flat;- it

ment of the film holder shown in Figure 8, it will be understoodby-referenceto- Fig. 18 that several fil-m recordsmay'be made at thesametime, each such record representing a particular-secti'on through thepatient or object. at distances apart correspondingtc the spacing-of thefilms (depending on the appropriate'magnification factor). Inasmuchassoine 'ofthe films (Fig. 18) are infront of-the film aXis oraxis ofrotation of the-support 55, while one 'may be on the axis and othersare-behindsuch axis, each film selects a different image correspondingto an objective planelocated parallel to the respective film andlocateda-distance' from the object axis similar to the film. from the filmaxis. 7 Y In-Figures 9 and 20 there is indicated apparatus similar:to'that shown in Figuresfi and 13 except that the grooves for thesupport of the films are curved asindicated at till; whereby a pluralityof sectional records are obtainedalong a curved surface with the imagerepresenting a sectionof the object having the same-curvature :as

thefilinor films. In Figures l -and 21 the grooves 60 are madeconcentric and-circularso that a pluralityof cylindrical sectionalpictures are obtained. InFigures 11 and22'the grooved! is made of spiralshape so asto obtain a.corre sponding record. Figures13 and 24 indicatethe i possibility of employing rectangular grooves 63 I and Figures 12and 23 radially disposed grooves 62. Obviously, however,intheconstruction of Figs.l3 and 24, all of the grooves occupied in any.one instanceii 1 Figures 15and 16 show a modification in the apparatuswhere it is contemplated that the film should only be progressivelyexposed to radiation for-the purpose of recording that section of theobject orpatient which it is desired to recordthereonr A light-tight box54 is employed and is supported upon the spigot l4; Asan additionalsupport there are two armstfi which carry sleeves 66' engaging theuprights 3i ofthe-structure for supporting the grid. Within thelight-tight'boxthere is a spool 67 carrying film- 68. The spool islocated behind a vertical screening wall-69 made of a material thatdoesnot permit X-rays topass therethrough. leaded. There is asecondspool ll] securedtoa shaft constituting an extension of .thespigot34;

The front side of the light-tight box is formedwith an aperture "H whichis controlled by shut' ters 12 of material that does not permit 'X-raysto pass therethrough. The shutters'li' maybe adjusted towards and awayfrom one :another so as to reduce or increase the eifective size of theaperture 11. For reasons which willibe'understood hereafter, it isdesirable to have the shutters 12 in order that the contrast in the filmrecords may be adjusted. In this case, preferably the film is leaded orotherwise made impermeable to X-rayson that surface opposite the surfaceintended to be irradiated by the X-ray beam..

The film may be rendered impermeable by the aid of lead foil in a mannerknownper se. In any case, the film bears a spacing means along one side,so that when it is rolled from the spool the layers of light sensitivematerial, upon the-.film.

63-cannot be- It may, for example, be

is-a base-member 5.5having apair ofuprights are spaced'from one"anotherby more than the actual-thickness.Iofthe film.

The spigot l4 associated with the light-tight box 64 does not, ofcourse, in'this case serve to rotate the. box. It-t is free thereof,whereby the spigot l4 rmay. cause rotation of the spool HI withoutaltering the position of the light-tight box. A beam'of X-rays indicatedat X in Figure 15 is allowed to fall upon the spool It. The spool Bl isloaded with the film 68; With rotation of the spigot M in the directionindicated by the arrow iniFigure 15, the film will be wound on 1e spool'Hl whilstit is exposed on its sensitive side to the'X-ray radiation. Bythe use of this typeof film carrier, it is possible to obtain a sharprecord of a spiralsection through the patient or object, undergoingirradiation.

It will now be understood how various types of records may bemadeinusing the invention and how-yet further modifications might be setforth. Moreover, while it is possible with the present invention toradiograph plane sections and curved sections simply by disposing thefilms in a preselected maner corresponding-tolthe section of the objectdesired, forthe sake of simplicitysuch will be referred to intheappended claims as parallel planes or 'plane parallel, although in casesof: curved sections this is naturalynot geometrically correct eventhough the sections will have the same curvature.

In the above described apparatus, it will be noted that thesource ofX-rays shown diagrammatically in Fig. 17 may consist-of anX-ray tubemounting of standardconstruction; theX-ray tube beingadjusted to arequired position and then'allowed to remain'in its position ofadjustment during the exposure of the film or the like. It will beappreciated from first principles that instead of rotating the patientor object undergoing .irradiation the X-ray tube'might itself be movedin correspondence with the movement of the film. A- construction ofapparatus where movement of the source of -X -rays is achieved is notdescribed indetail for the reason that, in most cases, the X-ray tubeand. its-mounting will necessarily be of considerable mass, and it willnot, in general be convenient for practical reasons to move the sourceof 'X-rays except wheresmall tubesare concerned. Moreover, since X- raytubes may be of delicatecon'struction, the swinging: movement thereof isfrom this aspect undesirable. However, ingeneraL-to satisfy theconditions of the inventiomit willsutfice if the source of X-rays, theobject orpatient irradiated,

and the recording'means, vizsthe film, are so rela- 1 tively disposed:that the film'ism'oved and the object 'or patient undergoing irradiationor the source of X-rays is moved in correspondence so that there is. aparticular-preselected plane or planes -(section or sections) irradiatedwhich re' main stationary with reference to-the recording means. It willthus become obvious to those skilledin the art thatan apparatus isherein provided for difierential radiography whereina radiograph of'asingle object-plane or section'of any preselected angulation may be madeor "a plurality. of object-planes simultaneously made. Moreover,continuous rotary motion is applied to thevobject and film axes whichare permanently vertically parallel to each other. Simply bypositioning-thefilmin any angular plane from the vertical to thehorizontal and whether on the film axis or spaced therefrom, any desiredobject-plane or planes may be automatically radiographed with:excellent-defm-ition. Also, a

- grid for the suppression of secondary radiations the presentinvention, regardless of the angle it is to be unde'rstoodthat otherembodiments of y plane ofsimultaneously a plurality of sections of v canbe readily employed with the apparatus of of the film relative to theobject axis.

Althoughseveral modifications of the present invention have been hereinshown and described,

the present invention may be made without departing from the spirit andscope of theapp'ended I plane or sections ofthe object, whichimageremains stationary relative to the rotating reclaims. i

What I claim is: i 1. The method of radiographing a particular an objectwhich consists in synchronously rotating the object to be radiographedand the image recorder about parallel vertical axes, subjecting theobject and image recorder to a beam of X- rays, the optical axis ofwhich intersects the parallel axes of rotation of the object and imagerecorder, and positioning the image recorder in a plane parallel to thepreselected plane or sec- 1 t I i-rays, ja carrier for animage recorderdisposed adjacent said object on the tions of the objectit is desired toradiograph.

2. The method of radiographing a particular plane or simultaneously aplurality of sections of an'object which consists in rotating the objectto be radiographed about a vertical axis, rotating the image recorderabout a vertical axis parallel to that of the object and in a horizontalplane below theobject plane, subjecting the object and image recorder toan angular beam of :X-rays having its focal point above the plane of theobject and in line with the image recorder and the optical axis of whichintersects the parallel axes of rotation of the object and imagerecorder,

and positioning the image recorder in a plane paralle to the preselectedplaneor sections of the object it is desired to radiograph.

3. An X-ray apparatus for producing radiographs of a particular planeor-simultaneously of a plurality of sections of an object comprising asource of X-rays, supporting means for the object to be radiographeddisposed adjacent said source of X-rays and rotatable about a verticalaxis, an image recorder disposed ad:- jacent said object support ontheside thereof opposite from said source of 'X-rays androtatimage'recorder with their rotation being so coordinated thatanimage of the preselected plane or sections of said object is cast by thesource of X-rays on said recorder by intersection of the optical axis ofsaid source of X-rays with the parallel axes of rotation of said objectsupport and said recorder, which image remains stationary relative tothe rotating recorder.

4. An X-ray apparatus for producing radiographs of a particular plane orsimultaneously of a plurality of sections of an object comprising asource'of X-rays, supporting means for the object to be radiographeddisposed adjacent said source of X-rays and rotatable about an axis topresent apreselected plane or sections of said object to the opticalaxis of said source of X-rays, a carrier for 'an'image recorder disposedadjacent said object on .the side thereof opposite from said source ofX-rays' and rotatable about an axis parallel tothe axis of said objectsupport, said image recorderjbeing adapted to preselect the desiredplane or sections of 1' the objectflto v same in; a-planeparallel tothat of thesecsaid source of X-rays tical axis parallelrto beradiographed by positioning the ,tion desired, andlmean'sqoperable tocause synchronous rotary: movement of said vobject supportand saidjected to said source of .X-rays, the optical axis; of which intersects,the parallel axesoi rotation of said object support and said recorder toprocarrier while the obj ect is subduce an image on said recorder of apreselected corder. I

apparatus for producing radioa source of X-rays, supporting means forthe object to'be radiographed disposed adjacent said j source ofpuX-raysvfor positioningthe object .in a plane below; that of said source of X-rays and rotatable about an axis to present a preselected plane orsections of, said'object to the source of side thereof opposite fromsaid source of "X-rays in a plane below that of the object to beradiographed and rotatalfe about an axis parallel to the axis of saidobject support, and means ing means and said carrier while the object issubjected to a beam of projecting angularly through the plane of saidobject and said recorder and intersecting the axes of rotation thereofto produce an image on said recorder of a preselected plane or sec- I'tions of the object,-Which image remains stationary relative totherotating recorder.

6. An X-ray apparatus for producing radiographs of a particular plane orsimultaneously of a plurality of sections of an object comprising asource of X-rays, supporting means for the object to be radiographeddisposed adjacent said X-rays from" said source operable to causesynchronous rotary movement'of said supportsource of X-rays androtatable about a vertical axis, an image recorder disposed adjacentsaid object supporton the side thereof opposite from said source ofX-rays and rotatable about a vertical axis parallel to that of saidobject support, said image recorder being adapted to preselect thedesired plane or sections of the object to be 'radiographed by'positioning the recorder in a plane parallel to that of the sectiondesired, means operable to simultaneously rotate said object support andsaid image recorder with their rotation being so coordinated that animage of the preselected plane or sections of said object is cast by thesource of X-rays on said recorder by intersection of the optical axis ofsaid source of X-rays with the parallel axes of rotation of said, objectsupport and said recorder, which image remains stationary relative tothe rotating recorder, and a grid positioned betweensaid object and saidimage recorder to prevent secondary radiation striking said imagerecorder.

7. An X-ray apparatus for producing radiographs of a particular plane orsimultaneously of a plurality of sections of an object comprising asource of X-rays, supporting means for the object to be radiographeddisposed adjacent said source of X-rays and rotatable about a verticalaxis, an image recorder disposed adjacent said object support onthe sidethereof opposite from that of said object support, said image recorderbeing adapted to preselectthe desired plane or sections of the objectand rotatable about a ver-' to be radiographed lay-positioning therecorder in a plane parallel to that of the section desired, mechanismoperable to simultaneously rotate said object support and said imagerecorder with their rotation being so coordinated that an image of thepreselectedplane or sections of said object is cast by the source ofX-rays on said recorder by intersection of the optical axis of saidsource of X-rays With the parallel axes of rotation of said objectsupport and saidrecordenwwhich image remains stationary relative to therotating recorder, and means for adjusting said image recorder relativeto said object-support Without affecting the operation of saidmechanism.

8. AnX-ray' apparatus for producing radiographs of a particular plane orsimultaneously as of a'plurality-ofsections of an object comprising asource of X-rays, supportingmeans for the object to be radiographeddisposed adjacent said source of -X-rays and rotatable about averticalaxis, an image recorder disposed adjacent said object support onthe-side thereof opposite from said source of X-rays and rotatable abouta vertical axis parallel to that of said object support, said imagerecorder being adapted to preselect thedesired plane or sections of therobject tobe radiographed by positioning the recorder in'a plane parallelto that of the section desired, mechanism operable to simultaneouslyrotate said object support and. said image recorder-With their rotationbeing so coordinated:

that an image of the preselected plane or sections of said object iscast by the source of X-rays on said recorder byintersection of theWILLIAM WATSON.

